A series of water soluble polymers have been developed, consisting of strictly alternating copolymers of polyethylene glycol (PEG, MW 1000 to 8000) and the amino acid lysine (Lys). When Lys is used as the amino acid component, a free carboxylic acid pendent group at each monomeric repeat unit is used to couple active agents. A series of studies has established the use of the PEG-Lys polymer for the delivery of cis-4- hydroxyproline (cHyp). cHyp is one of a series of proline analogues which have been shown to be a potent inhibitor of synthesis of collagen, and thus has been considered as a potential antifibrotic agent. However, free cHyp is too toxic to be used as a clinical agent, primarily due to its systemic effects on non-collagen proteins. To reduce the toxicity of this agent, cHyp was attached to the poly(PEG-Lys), and administered to rodents having experimentally induced pulmonary fibrosis. The poly(PEG-Lys-cHyp) was shown to be highly effective in these animal models, at dose levels that are three orders of magnitude below the toxicity levels of free cHyp. These preliminary results have shown that the delivery of cHyp via the poly(PEG-Lys) backbone to specific sites of active collagen formation is a potentially effective therapeutic strategy. A dry powder inhaler, previously tested for a variety of drugs including biopharmaceuticals, will be used during Phase I as the prototype delivery device. Successful development of pulmonary delivery of these sustained delivery agents will significantly accelerate their clinical development. PROPOSED COMMERCIAL APPLICATIONS: Currently, there are no effective treatments of pathological fibrosis available. General anti-inflammatory drugs, such as corticosteroids, are given clinically, but are only marginally effective. Although there are a number of companies which are engaged in anti-inflammatory and antifibrosis R&D, there is no competition for a site-directed therapeutic agent focused on diminishing pathological fibrosis.